1. Field of the Invention
The invention relates to a method and apparatus for transporting and dispensing containers and, more particularly, to a method and apparatus for transporting and dispensing containers in the form of a chain of open bags.
2. The Prior Art
The Autobag Patents disclose a packaging technique in which a chain of interconnected open plastic bags are used. In the earliest and simplest commercial form a roll of these bags was mounted on a mandrel and the mandrel was positioned in a box. A blower was connected to the box. Bags were fed, closed end first, out of a slot in the box. As the bags exited from the box, air from the blower exiting through the same slot as the bags, would inflate each bag as it came out of the box. A product was manually inserted into the inflated bag which was then separated from the chain. The loaded, separated bag was then closed and usually heat sealed.
The dispensing of bags of the type described in the Autobag Patents was initially accomplished with disposable shipping containers that also served as dispensing containers. As a next step in the evolution of eqiupment for effecting packaging with a chain of open bags on a roll, manually controlled dispensing machines were developed. These machines were adapted to receive coils of interconnected open bags. The bags were fed through a dispensing opening in the machine vertically downwardly along a path of travel. In a typical operation an operator would manually insert a product, after a bag had been blown open. The operator would then manually separate the bag from the chain of bags and insert the opening of the now loaded bag into a heat sealer. Concurrently with the separation of the now loaded bag the operator would feed the chain of bags to bring the next succeeding bag into the loading station.
More sophisticated relatively automatic equipment has been developed for loading and sealing chains of open bags on a roll. An example of such equipment is that disclosed and claimed in the H-100 Patents. With that equipment, bags are automatically fed to the loading station. In addition, they are automatically sealed and separated from the chain after products have been loaded in.
More recently, a machine for loading relatively large and bulky objects and relatively sharp objects into bags has been developed. This is the machine which is described and claimed more fully in the Horizontal Machine Patent where, like earlier machines and until the present invention was made, bags on a roll were used. With this machine, a bag being filled is supported in a generally horizontal orientation during loading so that the object being packaged is supported by the machine rather than the web as has generally been the case with other loading machines using bags on a roll.
While both chains of bags on a roll which have been sold under the trademark AUTOBAG and various machines for dispensing those bags have enjoyed outstanding commercial success, there are applications where bags on a roll create problems and indeed even some where they are unsatisfactory.
When a user operates a bag filling machine on a continuous basis, considerable operator attention and skill is required. In some applications, two rolls of bags are positioned side-by-side. The loading operation is started by feeding bags off one of the rolls. As the bags from the first roll are expended, a so-called flying splice is made to connect the first bag of the second roll to the last bag of the first roll. Obviously, the operator must pay attention to the extent to which bags have been expended off the first roll so that he is present and able to move swiftly once the last bag becomes accessible.
After the bags from one roll have been expended, the operator must remove the spent roll and mount another roll with a fresh supply of bags in its place. He must then be prepared to perform another flying splice when the bags from the second roll are expended.
In operations where two rolls and flying splices are not used, the packaging machine must be shut down when bags from a roll are expended. The operator then must remove the spent roll, insert a new roll, and manually feed the chain of bags in the new roll along the dispensing path through the machine. Preferably, he will stop the machine just as the supply of bags in the first roll is being exhausted, change rolls, and effect a splice and then restart the dispensing machine. This preferred technique obviates the need for manual feeding of the new chain along the machine's dispensing path.
Since feed from the roll is intermittent, there can be considerable starting and stopping. Alternately, bags may be fed from the roll continuously at a relatively slow rate and dancer rolls are used to maintain tension on the web section wending its way through the machine to a load station. The length of that web section shortens each time a new bag is fed to the dispensing station and then gradually increases as the bag at that station is loaded and then severed. Obviously, rather precise controls and relatively intricate mechanisms are required to effect this dispensing and the inertia of the rolls can be a problem. Accordingly, the size of a dispensing roll, and therefore the number of bags in a given roll, is limited by the inertia of the roll.
As larger and larger bags have been used in the bags on a roll concept, the problem attendant to manipulating the rolls has intensified and the numbers of bags which may be wound on the roll has reduced. As a consequence, the need to effect flying splices or alternatively to shut down a dispensing machine is more frequent and the efficiency of the overall system is reduced.